A herbicidal difluoroacetarnide derivative and its production process are disclosed in the U.S. Pat. No. 5,312,798. However, this process has a drawback in that it requires difluoroacetic acid which can be obtained from tetrafluoroethylene in a few steps-process but cannot readily be produced on an industrial scale (see, e.g., Org. Prep. Proced. Int., 19, 468 (1987)). Accordingly, there has been a great demand for developing an advantageous process for the production of fluoroalkanecarboxamide derivatives.